The present invention relates to a data processing apparatus suitable for the handling of a large amount of data, and in particular, to a data processing method in which specification (mapping) of registers can be changed without altering instructions.
Data processors operating with digitized multimedia data including video and voice data to display images thereof for the user have been rapidly broadly employed in various application fields of personal information facilities such as information appliances born on cars, terminal equipment for family amusement, and internet terminals.
To process a large amount of data in a data processor, it is necessary to establish a correspondence between many physical registers to logical registers which can be specified by instructions. For this purpose, the SPARC architecture of the Sun Microsystems Inc. has been broadly employed in many systems. Details of the system has been described in "Microprocessor", Nikkei Datapro, p. 1; MC1-303-801 to 808, 1960/6). According to the article, the system includes 32 registers which can be accessed for reference by instructions, i.e., eight fixed registers and 24 non-fixed registers arranged in a sequence. Each time a subroutine jump takes place, the 24 registers slide 16 registers in a first direction among a number of registers provided for non-fixed registers. For each subroutine return, the registers slide also 16 registers in a second direction reverse to the first direction.
In the conventional technology, the change in the mapping of logical registers to the physical registers can be accomplished only at timing of the subroutine jump or return. Furthermore, the sliding range in the registers cannot be arbitrarily determined. Namely, the sliding can be achieved only within a zone of successive physical registers. Therefore, a data processor can be applied, even when the number physical registers thereof is larger than the number of physical registers which can be specified by instructions, only to such processes as the subroutine jump and return. However, a data processor handling multimedia data and the like is required to carry out, in addition to the processes above, a concurrent process of a large amount of data according to parameters specified. For this purpose, it is essential that a large number of parameters are stored in the registers.